Solved When using Bukkit 1.12.2 my server crashes.

My server was working before with Bukkit. But randomly my server crashed and when I restart it crashed again. when I use "Vanilla Minecraft 1.12.2" it works. But whenever I use Bukkit 1.12.2 or Spigot 1.12.2 it crashes. I already deleted every plugin I used beforehand, but my server still won't work. I'm using server pro to run my server.

CONSOLE:

Loading libraries, please wait... [06:08:19 INFO]: Starting minecraft server version 1.12.2 [06:08:19 INFO]: Loading properties [06:08:19 WARN]: resource-pack-hash is deprecated and found along side resource-pack-sha1. resource-pack-hash will be ignored. [06:08:19 INFO]: Default game type: SURVIVAL [06:08:19 INFO]: Generating keypair [06:08:19 INFO]: Starting Minecraft server on *:41755 [06:08:19 INFO]: Using epoll channel type [06:08:20 INFO]: This server is running CraftBukkit version git-Bukkit-fbe3046 (MC: 1.12.2) (Implementing API version 1.12.2-R0.1-SNAPSHOT) [06:08:20 INFO]: Preparing level "EARTH" [06:08:21 INFO]: Preparing start region for level 0 (Seed: -993798221741288477) [06:08:22 INFO]: Preparing spawn area: 0% [06:08:24 INFO]: Preparing spawn area: 22% [06:08:25 INFO]: Preparing start region for level 1 (Seed: -993798221741288477) [06:08:26 INFO]: Preparing start region for level 2 (Seed: -993798221741288477) [06:08:26 INFO]: Server permissions file permissions.yml is empty, ignoring it [06:08:26 INFO]: Done (6.014s)! For help, type "help" or "?" [06:08:26 INFO]: Starting GS4 status listener [06:08:26 INFO]: Query running on 0.0.0.0:41755 [06:08:26 ERROR]: Encountered an unexpected exception net.minecraft.server.v1_12_R1.ReportedException: Ticking entity at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:754) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:371) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:651) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:555) [craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_172] Caused by: java.lang.ArrayIndexOutOfBoundsException: 1 at net.minecraft.server.v1_12_R1.PathEntity.f(SourceFile:74) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.DragonControllerFly.k(SourceFile:68) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.DragonControllerFly.j(SourceFile:63) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.DragonControllerFly.c(SourceFile:24) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.EntityEnderDragon.n(EntityEnderDragon.java:172) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.EntityLiving.B_(EntityLiving.java:1934) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.EntityInsentient.B_(EntityInsentient.java:246) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.World.entityJoinedWorld(World.java:1507) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.World.h(World.java:1482) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.World.tickEntities(World.java:1344) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.WorldServer.tickEntities(WorldServer.java:649) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:750) ~[craftbukkit-1.12.2.jar:git-Bukkit-fbe3046] ... 4 more [06:08:26 ERROR]: This crash report has been saved to: /home/gs/gs/data/servers/10259962/./crash-reports/crash-2018-06-26_06.08.26-server.txt [06:08:26 INFO]: Stopping server [06:08:26 INFO]: Saving players [06:08:26 INFO]: Saving worlds [06:08:26 INFO]: Saving chunks for level 'EARTH'/overworld [06:08:27 INFO]: Saving chunks for level 'EARTH_nether'/the_nether [06:08:27 INFO]: Saving chunks for level 'EARTH_the_end'/the_end

And also when I join my server, I get this message:
io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused:

 

@timtower Thanks so much, I guess after I spawned that ender dragon, I guess my server crashed. Thank you.